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Version: Python

How to use the Deephaven JSON viewer

Deephaven's UI can be used to display JSON objects. This guide shows how to build Deephaven with the NPM and PyPi JSON viewer packages, and how to use them in the UI.

Docker images

In order to display JSON objects in the Deephaven UI, you need to build Deephaven with custom dependencies. If you're unfamiliar on how to do this, check out the How to install packages guide.

We need to install dependencies on both the server and web images. Since we're building two Docker images, we'll put our Dockerfiles in separate directories: ./server/Dockerfile and ./web/Dockerfile.


Put the following in ./server/Dockerfile:


RUN pip install deephaven-plugin-json

This allows us to use the Python package in the console.


Put the following in ./web/Dockerfile:

FROM as build

RUN ./ @deephaven/js-plugin-dashboard-object-viewer

COPY --from=build js-plugins/ /usr/share/nginx/html/js-plugins/

This adds the object viewer plug-in to the Deephaven UI.


Next, we need to update the docker-compose.yml file to point to these images.

Local build

One option is to follow the docker build <path> pattern described in the How to install packages guide. We can run the following commands to build our Docker images.

docker build ./server --tag deephaven/custom-server
docker build ./web --tag deephaven/custom-web

Then, we update our docker-compose.yml file to point to these images.

image: deephaven/custom-server
image: deephaven/custom-web

docker-compose.yml build field

The other option is to remove the image field in the docker-compose.yml file and replace it with build. build would point to the directory of the Dockerfile.

build: ./server
build: ./web

Once this is done, we can run docker-compose build to build the images.


Once we've set up our Docker images, we can simply run docker-compose up to launch Deephaven.

In the console, run the following query to use the JSON plugin and view JSON objects in the UI.

from deephaven.TableTools import emptyTable
from deephaven.plugin.json import Node

t = emptyTable(100).update("X=i")
node_a = Node({'a': 'hello, world'})
node_b = Node({'b': 'goodbye', 't': t})